1. Experimental analysis of bladder reconstruction using atelocollagen sponge and cultured autologous cells:Twelve Japanese white rabbits were examined in this study. Under general anesthesia, mucosal layer and muscular layer were taken from the dome of the urinary bladder. These tissues were treated with enzymes,and were incubated in DMEM medium, separately. After serial culture, cells were seeded on atelocollagen sponge sheet, and were incubated in the same condition. After 1-2 weeks, bladder reconstruction was performed using this atelocollagen sponge. As a control group, rabbits were treated with non-seeded atelocollagen sponge. There was no difference in growth of epithelial and muscular cells between the 2 groups.2. Experimental reconstruction of the urinary bladder using atelocollagen-coated polyglycolic acid sheet in rabbit:Atelocollagen-coated polyglycolic acid ( C-PGA ) sheet was used in this experiment. Fourteen Japanese white rabbit were used. Before operation, C-PGA sheet was incubated with autologous blood ( pre-clotting,group 1 ), and was incubated with type1 atelocollagen ( group 2). After 2-12 weeks, rabbits were sacrificed. After 7 weeks, regrowth of muscle layer was seen, and tissue regrowth was better in group 1 than group 2.